For just a few panicky days Apophis became the first and so far only near-Earth object to reach four on the Torino scale of impact hazards, where zero equals next to no risk and 10 means that a collision is certain with something big enough to threaten the planet. Even that four rating translates as Apophis being more than 97% likely to miss the Earth.
Further observations got that rating drastically downgraded within the week but by then Apophis had been splashed all over the media and become embedded in our cultural consciousness as the “doomsday asteroid”. It has had numerous name checks in poem and song – notably in The Profits of Doom by goth metal outfit Type O Negative (aka “The Drab Four”), which mentions Friday 13th 2029 and how “this stone’s called Apophis; it brings Apocalypse”. Even more impressively, it’s the jumping-off point for 2011 video game Rage, which unfolds in the aftermath of global devastation initiated by a collision with Apophis.
What may also have contributed to our willingness to get into such a lather is that it hit the headlines only a few years after the Earth-imperilled-by-asteroid blockbusters Armageddon and Deep Impact hit multiplexes, giving us further cause to watch the skies. Apophis fitted with what we’d learned from the movies – that we are at the mercy of a capricious cosmos – so it became a focus of fear.
Now, thanks to observations made during its 2013 intersections with our orbit, Apophis is a big fat zero on the Torino scale for all 19 of its Earth fly-bys over the next century. So too are all but one of the hundreds of other Near Earth Objects that Nasa gives a rating to. Even the exception – 2007 VK184 – only scores one because there is an estimated teeny tiny chance (one in 1,820) that it could hit us on 3 June 2048. Probably not worth putting in your forward planner, then.
So, there appears to be no real cause for alarm about any of the many, many chunks of space rock we know of that are out there. But, if you do want something to worry about then bear in mind that – with apologies to Hamlet – there are more things in the heavens and potentially headed to Earth than are dreamt of in our philosophy. Last year, 2012 LZ1 – an asteroid three times bigger than Apophis – was only spotted for the first time four days before its closest approach to Earth. Who’s to say that next time we might have even less notice about something headed straight for us?